At first sight an odd thing to want to do, but when your parents are elderly with reduced grip and the grand children are all teenagers, being able to get the tops off house hold cleaner is more important than the non risk (in their home) of a toddler consuming something deadly. Here I'm dealing with the simplest form of child proof top and oddly the one that gives my parents the most trouble.
A pair of lugs in side the neck of the cap engage on teeth on the neck of the bottle and stop it being undone unless pressure is applied to deform the cap
Step 1: 2 Cuts
The solution is straight forward.
With your cutting blade of choice, slice off the lugs and smooth the inside of the cap.
The cap is now just a standard screw cap, it can now be done up fully and removed with out problem. Where as previously it has been just dropped back in place resulting in spills and drying out of the cleaning product in the bottle.